[R] unicode variable and function names?
murdoch.duncan at gmail.com
Tue Jan 4 02:32:52 CET 2011
On 11-01-03 7:44 PM, stvienna wiener wrote:
> Dear List,
> Is it possible to have function names like ∀ (unicode universal quantifier)?
> This question is inspired by agda source code, which supports this.
> It would be handy to use. My guess is, however, that it's not supportet in R.
Why not just try it? I get this:
> ∀ <- 1
Error: unexpected input in "‚"
> `∀` <- 1
i.e. it is seen as a non-syntactic name, so needs backquotes to be used,
but then it's fine (except it's probably a bad idea, since non-UTF8
systems will have trouble with it). Looks like the error message needs
I was surprised how hard it was to find this documented, but it is there
in the Introduction to R manual in section 1.8, "R commands, case
sensitivity, etc." Someday someone should add this to the Language
Definition manual. The rule is that syntactic names need to start with
. or a letter, and contain only letters, digits, . and _. The confusing
part is that "letter" doesn't have a universal definition, so the manual
suggests limiting them to ASCII letters.
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